Improved screw-driver



. f @uitrit tetra gamut t'fit.

JARED A. AYRES, OF HARTFORD, CONNECTICUT, ASSIGN OR TO NATIONAL SCREW COMPANY, OF SAME PLACE.

Letters Patent No. 67,014, dated July 23, 1867.

IMPROVED SCREW-DRIVER.

TO ALL WHOM IT MAY CONCERN:

Be it known that I, JARjED A. AYRES, of Hartford, in the county of Hartford, and State of Connecticut, have invented a. new and useful Improvement in Screw-Drivers; and I do hereby declare that the following is a full, clear, and exact description of the construction and operation of the same, refereucebeing had to the accompanying drawings and the letters of reference marked thereon.

- Figure 1 is a side 'view of the improved screw-driver, `showing the edge of the blade.

Figure 2 is a. side view of the same, showing Vthe atside of the blade.

'My invention consists in making the edge of the screw-driver which enters the head of the screw of a. dovetailed form,ias shown at a, figs. 1 and 2. This dove-tail is made by putting aways. portion 'of the metaly just buck of the edge, as shown in the drawings, or by upsetting the end, or in any manner by which the part entering the screw is maldefof 'the described form. i

The operation of this improved screw-driver is such that being lplaced in the slot of an ordinary screw the ltendency to slip out is avoided, particularly if the slot in the head ofthe screw be likewise of a; dove-tailed form. In this latter case the force used in turning the screw binds the screw-driver in its place, and presses it into the head of the screw, rather than out, as is the case with an ordinary screw-driver.

v Gleim. What I claim as my invention, and desire to secure by Letters Patent, is-L A screw-driver with a dove-tailed edge, substantially as herein described.

'J'. A. AYRES.

Witnesses:

F. CHAMBERLIN, M. W. CHAMBERLIN. 

